8 Optagne abstracts ved NBC5 M e d i c o A Review of Telemedicine Services in Finland Vikramajeet Khatri, Carrie B. Peterson, Sofoklis Kyriazokos, Neeli R. Prasad Center for TeleInfrastruktur (CTiF), Aalborg University, Aalborg, Denmark Abstract: Telemedicine is gaining popularity due to the provision of ubiquitous health care services that is a fundamental need for every socialized society. In this paper, telemedicine services in Finland are discussed, as well as how they came into existence, how they are funded, evaluated, and what are their impacts on health care systems and society. Telemedicine services like teleradiology, telelaboratory, telepsychiatry and remote consultations, are being offered in all hospital districts. Primary health care centers in Finland are lacking telemedicine services, and are planning to have them. Electronic Patient Records (EPR), with e-referral and e-discharge letters, have prevented patients from unnecessary repeated laboratory examinations and treatments. The e-archive (Finland s national EPR) is in the planning stage, making EPR on national level, to promote ease of access to patient records and ubiquitous care. The e-prescription project is also in the planning stage, which aims to enhance drug safety, prevent forged prescription, and prevent threat to a patient s life. Keywords: Telemedicine, Teleradiology, Finland, Ubiquitous Care Repeatability of pressure oscillation amplitudes during the interrupter measurement of respiratory resistance J.Kivastik, J.Talts, K.Jagomägi, R.Raamat, M.Vasar Department of Physiology, University of Tartu, Tartu, Estonia Children s Clinic, University of Tartu, Tartu, Estonia Abstract: Interrupter resistance (Rint) technique for assessing respiratory mechanics requires minimal cooperation and can therefore be successfully performed in young children. Analysis of recorded oscillations of the mouth pressure (Pmo) has been suggested to provide additional indices of change in airway mechanics. The aim of this study was to establish the repeatability of pressure oscillation amplitudes. Children performed two sets of Rint measurements. Further analysis of Pmo tracings was performed using MATLAB software. Pmo data were normalized to the last recorded pressure and afterwards oscillation amplitudes (Amp) were found as the difference between the first Pmo maximum and minimum. Intra-measurement repeatability was assessed by the coefficient of variation (CV) and between-test repeatability by the coefficient of repeatability (CR). 9 young children (aged 3 to 7 years) were studied (49 of them healthy, 8 wheezers and 5 coughers). Median CV values for both measurements were 4% and 5% for Rint, and 4% and 3% for Amp. Our betweentest Rint repeatability was similar to that of previous studies (CR was 0.3 kpa L - s or 33.3% of baseline value). CR for Amp was 0.4 or 7.6% of baseline value. There was no significant difference between groups of children. We measured short term repeatability for the most simple pressure oscillation amplitude and found that this is similar to Rint repeatability. Keywords: airway resistance, interrupter Finite Element Implementation of a Structurally-Motivated Constitutive Relation for the Human Abdominal Aortic Wall with and w i t h o u t A n e u rys m s M.S. Enevoldsen, K.-A. Henneberg, L. Lönn and J.A. Jensen Biomedical Engineering, Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark Department of Radiology and Department Vascular Surgery, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark Abstract: The structural integrity of the abdominal aorta is maintained by elastin, collagen, and vascular smooth muscle cells. Changes with age in the structure can lead to development of aneurysms. This paper presents initial work to capture these changes in a finite element model (FEM) of a structurally-motivated anisotropic constitutive relation for the four fiber family arterial model. First a D implementation is used for benchmarking the FEM implementation to fitted biaxial stress-strain data obtained experimentally from four different groups of persons; 9-9 years, years, 6-79 years and abdominal aortic aneurysm (AAA) patients. Next the constitutive model is implemented in an anisotropic 3D FEM formulation for future simulation of intact aortic geometries. The D simulations of the biaxial test experiment show good agreement with experimental data with a standard deviation below 0.5% in all cases. The maximum axial and hoop stress in the group of AAA patients was 94.9 kpa (±0.83 kpa) and 94.3 kpa (±0.4 kpa) at maximum stretch ratios of.043 and.037, respectively. In the 3D simulations, the maximum stress is also found to occur in the AAA patient group, with the highest stress in the circumferential direction (75 kpa). Comparison with an already published isotropic model indicates that the latter underestimates the peak stress significantly. Based on these results it is concluded that the four fiber family model has been successfully implemented into a 3D anisotropic finite element model and that this model can provide more accurate insight into the stress conditions in aortic aneurysms. Keywords: Biomechanics, aortic aneurysms, four fiber family model, anisotropic finite element analysis.

9 Optagne abstracts ved NBC5 Assessment of the optical interference in a PPG-LDF system used for estimation of tissue blood flow J. Hagblad, M. Folke, L.-G. Lindberg and M. Lindén Mälardalen University, School of Innovation, Design and Engineering, Västerås, Sweden Linköping University, Department of Biomedical Engineering, Linköping, Sweden Abstract: The aim of this study is to assess the optical cross interference in a system including laser Doppler flowmetry (LDF) and photoplethysmography (PPG) with regard to the illuminating power of PPG-LEDs and distance between the light detector/s and light source/s. Reduced or missing blood perfusion can lead to pressure ulcers. Monitoring changes in blood flow in areas prone to pressure ulcer development would be a valuable tool for prevention of pressure ulcer development. The probe, with one to two LDF-channel/s and two PPGchannels (PPGG/560 nm and PPGIR/80 nm), covers 0 cm x 0 cm. Influence from PPG-LEDs to the LDF-system and influence from the LDF-laser to the PPG-system was investigated. Three different light intensities were used for the PPG-LEDs. Recordings were repeated using two different placements of the LDF fibre, changing the distance between light source/s and light detector/s of the reciprocal technique. The LDF did not show any influence from light from the PPG. PPGG is more affected by laser light than PPGIR. Laser light influenced PPGG, most at lowest intensity of the PPGLEDs. The influence of the laser light to the PPG-channels is less in the outer position of the LDF-fibre. Interference can be totally avoided by switching, only measuring by one technique at a time. Rapid flow changes are then not possible to monitor fully. When rapid blood flow variations at different vascular depths are of interest to monitor, placement of the LDF-fibre in the outer position and use of a higher light intensity of the PPG-LEDs might be an alternative. However, interference still can be present, and further, the measurement volume of LDF will be different from that covered by PPG-channels. Keywords: PPG, LDF, interference, peripheral flow, pressure ulcer A flexible sensor system using resonance technology for soft tissue stiffness measurements evaluation on silicone Anders P Åstrand,3, Ville Jalkanen,3, Britt M Andersson,3, Olof A Lindahl,3 Department of Applied Physics and Electronics, Umeå University, Umeå, Sweden Department of Computer Science, Electrical and Space Engineering, Luleå University of Technology, Luleå, Sweden 3 Centre for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden Abstract: One of the most common forms of cancer among men in Europe and the United States is prostate cancer. The cancerous tissue is less soft, and has different biomechanical properties compared to healthy tissue. It has been shown that tactile sensors can be used to distinguish this difference. If a piezoelectric sensor is set to oscillate at its resonance frequency through a feed back circuit, a frequency shift is observed when the sensor comes in contact with a surface. This shift can be correlated to the stiffness of the tissue. A flexible instrument has been developed, with which it is possible to scan both flat and spherical bodies and where the sensor can be tilted to have different contact angles. Measurements performed in this study on flat silicone discs of different stiffness showed a relationship between both the frequency shift and the impression depth for the different silicone discs, when a constant force was applied. The results are promising for future studies on silicone with different geometries and finally on prostate tissue to complete the evaluation. Keywords: Resonance sensor, Piezoelectric, Prostate cancer, Detection, Frequency shift Supervised Neuro-Fuzzy Biofeedback for Computer Users A. Samani, A. Kawczyński and P. Madeleine Center for Sensory-Motor Interaction (SMI)/ Department of Health Science and Technology, Aalborg, Denmark Department of Athletes Motor Skills, Sport Institute, University School of Physical Education, Wroclaw, Poland Abstract: The design of an advanced biofeedback system was introduced using neuro-fuzzy concept. Eleven healthy volunteers took part in six sessions over two weeks in which computer work was performed for 0 min. The six sessions were divided into two identical parts where each part was taken place in two consecutive days. After the first session, the subjects underwent excessive eccentric exercises of shoulder elevation to induce muscle soreness. The second session was performed immediately after the exercises and third session 4 hours after the exercises. The second part was performed exactly one week after the first part. Surface electromyography (EMG) of descending and ascending trapezius, deltoideus anterior and serratus anterior was recorded. Linear and nonlinear indices of muscular load were calculated from EMG signals. The first session was utilized as the benchmark of normal muscle condition during computer work and all the rest as malfunctioning/altered condition. A neuro-fuzzy system was trained and tested to discriminate between the first session and all the rest. Using a greedy forward search strategy most discriminative features were found. A high sensitivity ~90% but a low specificity ~60% was observed. It was concluded that apart from the trapezius, the deltoideus and serratus anterior should also benefit from a biofeedback design. Combining of such system with timing constraint on biofeedback alarming can render a viable biofeedback system aiming at preventing musculoskeletal disorders. Keywords: delayed onset muscle soreness, sample entropy, permutation entropy, extended permutation entropy, work related musculoskeletal disorders. MTI 3 9

10 Optagne abstracts ved NBC5 Possibility to use Finapres signal for augmentation index estimation K. Pilt, K. Meigas, M. Viigimaa and K. Temitski Tallinn University of Technology/Department of Biomedical Engineering, Tallinn, Estonia Abstract: The possible method for augmentation index estimation from a Finapres signal is described. The experiments were carried out on volunteers. The augmentation indices were calculated from the Finapres signal by using the proposed method and compared with the Sphygmocor reference device. As result the correlation between Sphygmocor and Finapres augmentation indices was found to be r=0.8 (p<0.00) and the regression model was constructed. Keywords: Augmentation index, pressure wave, derivatives, Sphygmocor, Finapres. Onto-oncology: a mathematical physics unifying the proliferation, differentiation, apoptosis, and homeostasis in normal and abnormal morphogenesis and neural system. K. Naitoh Waseda University, Faculty of Science and Engineering, Tokyo, Japan Abstract: The macroscopic theory describing the rhythmical morphogenetic process and the standard circuit in brain (Naitoh, Proc. of ICBME, 008 & JJIAM 0) also reveals the essential features underlying cancer expanding infinitely, which is with proliferation, differentiation, apoptosis, and homeostasis. Extremely large number of molecules in healthy and cancerous processes can be classified into six macroscopic groups. Then, the macroscopic theory, which is based on an ordinary differential equation system with only six variables, will bring a new fundamental platform for eradicating cancer. Keywords: Sevenfold beat, ontogeny, apoptosis, cancer, brain, neural network Characterization of Pathological Tremor from Motor Unit Spike Trains J.L. Dideriksen, J.A. Gallego and D. Farina,3 Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark Bioengineering Group, Consejo Superior de Investigaciones Cientificas, Madrid, Spain. 3 Department of Neurorehabilitation Engineering, Bernstein Center for Computational Neuroscience, University Medical Center Göttingen, Georg-August University, Göttingen, Germany Abstract: Pathological tremor is the involuntary oscillation of a limb and is related to a diversity of diseases. Using a newly developed computational model for simulating surface EMG and complete discharge patterns of the motor unit population under the influence of neural oscillations in the central nervous system, the use of motor unit spike trains to characterize pathological tremor was investigated. Simulations were performed in conditions, including different types of pathological tremor and varying levels of voluntary activity. The results showed that the cumulative spike trains of at least 5 motor units provided a better estimate of the central oscillations that it could be obtained from surface EMG in approximately 50% of the simulated conditions. In the remaining conditions there was no significant difference. The results indicate that motor unit spike trains constitute a useful signal for characterizing pathological tremor in vivo. Keywords: Tremor, motor unit, electromyography, neuromuscular model. Quantification of Indoxyl Sulphate in the Spent Dialysate Using Fluorescence Spectra. J. Holmar, J. Arund, F. Uhlin,, R. Tanner and I. Fridolin Department of Biomedical Engineering, Tallinn University of Technology, EST-9086 Tallinn, Estonia Department of Nephrology, University Hospital, Linköping, S Linköping, Sweden Abstract: The aim of this study was to investigate the possibility to determine the amount of Indoxyl Sulphate (IS) in the spent dialysate using fluorescence spectra. Eight uremic patients from Linköping were studied during their three dialysis treatments in one week at the Department of Dialysis and Nephrology at Linköping University Hospital. Dialysate samples were taken during each treatment and analyzed, IS concentration was estimated using HPLC method, and fluorescence spectra was measured with spectrofluorophotometer. The fluorescence spectral values were transformed into IS concentration using regression model from total material noted as fluorescence method (F). Achieved results were compared regarding mean values and SD. Mean value of IS estimated by HPLC was.±0.77 mg/l and by F.±0.7 mg/l. Concentrations were not significantly different (p 0,05). This study indicates, that it is possible to estimate the concentration of IS using only fluorescence values of the spent dialysate. Keywords: Indoxyl Sulphate, dialysis, fluorescence, spectra, uremic toxins.

11 Optagne abstracts ved NBC5 3D Numerical Model of the Middle Ear Geometry based on micro CT imaging M. Kwacz, J. Wysocki and P. Krakowian 3 Warsaw Technical University/Faculty of Mechatronics, Warsaw, Poland Institute of Physiology and Pathology of Hearing, Warsaw, Poland 3 Institute of Fundamental Technological Research PAN, Warsaw, Poland Abstract: Modelling of the sound transmission process from the external ear canal through the middle ear structures to the cochlea is often performed using the finite element method. This requires knowledge of the geometry of the object being modelled. The paper shows the results of the numerical reconstruction and create the 3D numerical model of the middle ear geometry. The micro CT images of a cadaver s temporal bone were used to carry out the reconstruction process. The obtained geometry may be used not only for modeling of the middle ear mechanics before and after ossicular replacement but also for production of anatomical middle ear prostheses, calculation of inertial properties of the ossicular bones or educating radiologist and otolaryngologist. Keywords: middle ear, micro-ct, 3D geometry. Preliminary Experimental Verification of Synthetic Aperture Flow Imaging Using a Dual Stage Beamformer Approach Ye Li and Jørgen Arendt Jensen Center for Fast Ultrasound Imaging, Dept. of Electrical Engineering, Technical University of Denmark, Lyngby, Denmark Abstract: A dual stage beamformer method for synthetic aperture flow imaging has been developed. The motivation is to increase the frame rate and still maintain a beamforming quality sufficient for flow estimation that is possible to implement in a commercial scanner. With the new method high resolution images can be obtained continuously, which will highly increase the frame rate. The flow velocity is estimated by using a time-domain cross-correlation technique. The approach is investigated through experiments with the SARUS scanner (Synthetic Aperture Real-time Ultrasound System). A flow rig generates a parabolic laminar flow, and the SARUS scanner is used for acquiring the data from individual channels of the transducer. The experimental results showed that increasing the number of imaging lines used for the estimation form 4 to 4 reduces the standard deviation from % to 7.6%. The parameter study showed that the number of crosscorrelation functions for averaging and length of the search range influence the performance. Keywords: Synthetic aperture flow imaging, synthetic aperture sequential beamforming, SARUS. An fmri Investigation of Auditory Pathway Using Different Paradigms a n d A n a lys i s P ro c e d u r e s M. Ryn, E. Charyasz, M. Erb and U. Klose Diagnostic and Interventional Neurardiology, University Hospital Tuebingen, Germany Abstract: The purpose of the study was to improve the visualization of the auditory pathway using different paradigms and analysis procedure of functional magnetic resonance imaging (fmri). In particular, the signal of white matter (WM) was used in statistical analysis to remove distortions and improve the quality of correlation maps. Ten healthy volunteers were examined on a 3T scanner with music stimulation and three different paradigms: block design, continuous sound and resting state. The auditory pathway could successfully be visualized. Development in post-processing using the repetition time and WM as regressors and also correlation analysis provided an improvement in visualization of cortical as well as subcortical structures. The results demonstrate a tight functional relation between auditory cortex and brainstem areas in the human brain. Keywords: Functional magnetic resonance imaging, brainstem, auditory cortex, white matter, correlation. Spatiotemporal QRST C ancellation Method for 3-lead ECGs C. Klamor, K. Grimmel, N. Lentz, A. Bolz Karlsruhe Institute of Technology (KIT), Institute for Biomedical Engineering (IBT), Karlsruhe, Germany Abstract: The analysis and characterization of atrial tachyarrhythmias like atrial fibrillation (AF) require an extraction of the atrial activity (AA) from present ECG recordings by eliminating all ventricular activity (VA). This contribution develops a new QRST cancellation approach with an independent component analysis (ICA) for 3-lead ECG recordings. The small set of leads leaves residual parts of the QRS complex in the extracted AA. Therefore a post-processing with a discrete wavelet transformation (DWT) is used to detect position and duration of all remaining QRS complexes for further elimination. The result is a VA-free signal sequence describing only the AA which offers the requirement for a safe AF frequency determination needed for further characterizations. Keywords: ECG, QRST cancellation, blind source separation, wavelet transformation MTI 3

12 Optagne abstracts ved NBC5 Pressure algometry and tissue characteristics: Improved stimulation efficacy by a new probe design S. Finocchietti, L. Arendt-Nielsen, T. Graven-Nielsen Laboratory for Musculoskeletal Pain and Motor Control, Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Denmark Abstract: Pressure algometry is broadly utilized to assess deep tissue sensitivity. In this study the relation between pressure-induced pain in humans and stress/strain distribution within the deep tissue was evaluated. A 3-dimensional finite-element computer model was utilized to describe stress/strain distribution in tissues of the lower leg during pressure stimulation. The computer model was validated based on data recorded by computer-controlled pressure-induced muscle pain in 6 subjects. An indentation of 7 mm was sore for all subjects and at this level data were extracted from each simulation. Simulations were performed with two probe designs (cylindrical and semispherical). The principal stress peaked in the skin and was decreased to about 0% in the underlying muscle tissue. The principal strain peaked in adipose tissue and was reduced in muscle tissue to 80%. The probe evoked a strain peak in adipose tissue at 0. (cylindrical) and 0.4 (semispherical); in muscle tissue 0.0 and 0.0 respectively. The shear strains were also reduced using the semispherical tip. The human pressure pain thresholds with the semispherical tip were significantly smaller compared with the flat probe (P<0.05). The results suggest that pressure-induced muscle pain is most effectively induced by semi spherical probes, while flat ones activate superficial structures. The probe design is considered an important factor during pressure pain assessments and should take into account when performing clinical studies. Keywords: pressure algometry, muscle pain, finite element Analysis of the auditory perception of ultrasound Doppler signals to improve pregnancy risk assessment M. Ewerlöf, A. Thuring, K. Maršál, T. Jansson Department of Electrical Measurements, Lund University, Lund, Sweden Department of Obstetrics and Gynecology, Lund University, Lund, Sweden Abstract: In high-risk pregnancies, the transport of oxygen and nutrients from maternal to fetal blood via the placenta is often impaired. To assess the risk, pulsed Doppler ultrasound (US) is used to evaluate the flow velocity waveform in the umbilical artery with the pulsatility index (PI), which is derived from the velocity envelope of the Doppler power spectrum. However, simply listening to the Doppler signal can indicate to an experienced sonographer that the type of the blood flow is worse than the PI suggests. This is however dependent on the operator s experience and it may be difficult to estimate what influences the subjective judgement. Motivated by the description of the Doppler sounds by an experienced operator (AT) as having a timbre, this study describes an analysis of Doppler sounds in search for an index or method with capacity to better evaluate the blood flow in the umbilical artery in high-risk pregnancies. A test was designed, where synthetically produced Doppler sounds with various spectral contents were played together with a variable sinusoidal sound signal. The task for the five test persons was to match the frequency of the sinusoidal signal to the Doppler sounds. The tests indicated that the human ear is most sensitive to the lower frequencies of Doppler sounds. An analysis of prerecorded sounds showed a difference in the lower frequencies of a sound considered to emanate from the umbilical blood flow of healthy fetuses with normally functioning placenta as compared to a pathological one. This might explain the difference between the sounds experienced by an operator. As a suggestion to extract more information than the maximum envelope, the minimum frequency envelope was extracted from pre-recorded clinical sounds. Based on the pilot tests presented here, this shows to be a promising strategy. Keywords: synthetic Doppler signal, pulsatility index, flow velocity waveform, umbilical artery blood flow Telerehabilitation for COPD patients across sectors: using technology to promote cooperation among healthcare professionals B. Dinesen, O.K. Hejlesen,, S.K. Andersen, Egon Toft Department of Health Science and Technology, Aalborg University, Aalborg, Denmark Department of Health and Nursing Science, University of Agder, Norway Abstract: A telerehabilitation programme for patients with chronic obstructive pulmonary lung disease has been developed. Aim: The aim of the paper is to explore how telerehabilitation technology influences cooperation and coordination between healthcare professionals in the Telekat network. Theory: Network theory has been applied. Methods: A triangulation of data collection techniques such as documentary materials, participant observations (n=63 hours), and qualitative interviews (n=4) has been used in a case study of the Telekat project. Findings: Telerehabilitation technologies influences cooperation and coordination between healthcare professionals in themes like: interdisciplinary decision making, mutual learning processes and new professional roles. Conclusion: A combination of telerehabilitation technologies is a facilitator for cooperation and coordination between healthcare professionals in a network. Keywords: Co-operation, coordination, tele-rehabilitation, healthcare professionals

14 Optagne abstracts ved NBC5 Examples of Vector Velocity Imaging Peter M. Hansen, Mads M. Pedersen, Kristoffer L. Hansen, Michael B. Nielsen and Jørgen A. Jensen Department of Radiology, Section of Ultrasound, Rigshospitalet, Copenhagen, Denmark Center for Fast Ultrasound Imaging, Dept. of Elec. Eng., Technical University of Denmark, Lyngby, Denmark Abstract: To measure blood flow velocity in vessels with conventional ultrasound, the velocity is estimated along the direction of the emitted ultrasound wave. It is therefore impossible to obtain accurate information on blood flow velocity and direction, when the angle between blood flow and ultrasound wave approaches 90. The majority of the vessels in the human body is parallel to the surface and therefore positioned in a way that prevents proper placement and angulation of the transducer, when the velocity and direction of blood flow is to be estimated. Different techniques to circumvent this problem have been tried including Transverse Oscillation. This method has been tested in computer simulations, on flow phantoms and in-vivo, and subsequently validated against MRI angiography. Transverse Oscillation is now implemented in a commercial ultrasound scanner from BK Medical (UltraView). In this article UltraView is demonstrated on the carotid artery, jugular vein and femoral vein that all runs almost parallel to the skin and thus is angled near 90 to the ultrasound waves. Arterial and venous simple and complex flow with formation of vortices is demonstrated by scanning on the longitudinal axis with a 90 angle on the vessel. Moreover secondary flow in the abdominal aorta is illustrated by scanning on the transversal axis. Keywords: Transverse oscillation, vector velocity, blood flow, velocity estimation. An approach to a multiple channel oximetry system A.G. Mohammedani, K. Mankodiya,5, A. Opp, H. Gehring 3, M. Klinger 4 and U.G. Hofmann Institute of Signal Processing, University of Luebeck, Luebeck, Germany Institute of Medical Engineering, University of Luebeck, Luebeck, Germany 3 Department of Anesthesiology, University Hospital of Schleswig-Holstein, Campus Luebeck, Luebeck, Germany 4 Institute For Anatomy, University of Luebeck, Luebeck, Germany 5 Dept. of Rehabilitation Science & Technology, University of Pittsburgh, Pittsburgh, USA Abstract: Monitoring the oxygen saturation is a standard procedure during surgical intervention and on intensive care units. A common way is to measure the arterial saturation at various locations such as the finger or the forehead. Cardio vascular interventions such as coronary bypass surgery require additional monitoring of the cerebral oxygenation. Commercial devices are bulky and allow for processing one measurement parameter only. The multiple channel oximetry system introduced here has the ability to non-invasively measure and process both the arterial and the cerebral oxygen saturation. It is an optical method that utilizes absorption of light at specific wavelength emitted by LEDs. The present work introduces such a device as well as two different sensor positions for the arterial saturation. Here the signal quality in terms of SNR is compared at the different locations. Heart of this device is an embedded smart phone processor which allows for both driving the LED circuit and processing data. Keywords: NIRS, cerebral, pulse, oximetry, brain. Phonocardiographic recordings of first and second heart sound in determining the systole/diastole-ratio during exercise test S.M.M. Rønved, I. Gjerløv, A. Brokjær and S.E. Schmidt Department of Health and Science technology, Aalborg University, Aalborg, Denmark Abstract: The objective was to examine whether a microphone can be used to detect first and second heart sound during an exercise test and if these recordings can be used to calculate S/D-ratios in healthy subjects. Furthermore the objective was to describe the changes in systolic and diastolic duration under cardiac stress. Nine healthy subjects (5M, 4F) completed a standardized exercise test while wearing a Panasonic microphone incorporated in a specially designed coupler. Recordings of heart sounds were made with Acarix Data Acquisition System at the end of each workload level. As heart rate increased, the recordings became more difficult to interpret as did detection of first and second heart sounds. Recordings from female subjects were easier to interpret than those of male subjects. As heart rate increased, the S/D-ratio increased accordingly. The development of systole and diastole duration was very similar in male and female subjects. First and second heart sound can be detected using a microphone, but noise at higher load levels necessitates the development of a noise-reducing filter. Furthermore the duration of systole and diastole was found altered during stress. The systole duration decreased minimally whilst the diastole duration decreased markedly as a function of higher heart rate. Keywords: Ischemic heart disease, heart sounds, exercise test, S/D-ratio, microphone.

15 Optagne abstracts ved NBC5 An influence of multiple affecting factors on characteristic ratios of oscillometric blood pressure measurement J.Talts, R.Raamat, K.Jagomägi, J. Kivastik Department of Physiology, University of Tartu, Tartu, Estonia Abstract: We studied how interactions between the arterial pressure pulse and mechanical characteristics of the arterial wall and occluding cuff can modulate the characteristic ratios used for oscillometric estimation of systolic and diastolic blood pressures (k syst and k diast, respectively). Using an integrated artery cuff pressure/volume model with different arterial pressure pulses as input signals we obtained the oscillation envelopes and calculated characteristic ratios. For the tested range of affecting factors, k syst varied from 0.4 to 0.8 and k diast from 0.56 to This gives evidence that oscillometric estimation may lead to substantial inaccuracies if fixed characteristic ratios are used. Errors can be reduced by considering changes in the pulse pressure amplitude and in the symmetry index of the artery-cuff pressure/volume relationship. Keywords: Oscillometric blood pressure, characteristic ratio, accuracy of measurement, modeling The Properties of the Missing Fundamental of Complex Tones T. Matsuoka, and Y. Iitomi MIT, Cambridge, U.S.A. Faculty of Engineering, Utsunomiya University, Utsunomiya, Japan Abstract: The existence of the missing fundamental phenomenon is known, but its mechanism is unknown. We showed how the information of the missing fundamental f0 explicitly appeared on the aggregated autocorrelogram of the output pulse train for input signal f to one cochlear model and the output pulse train for input signal f to another cochlear model (where f=nf0 and f=(n+k)f0). In practice, we listen to a complex tone of f and f with each ear. In this paper, we try to investigate the influence of the pitch and the number of harmonic components of complex tones on perceiving the missing fundamental. Keywords: the missing fundamental, complex tone, perception, cochlear models experiment. Muscle strength as a predictor of the magnitude of multidirectional force fluctuations during steady contractions S.E. Salomoni, T. Graven-Nielsen Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Denmark Abstract: It has been shown that, during static contractions, the standard deviation of force increases linearly as the target force increases due to the orderly recruitment of motor units. In addition, previous studies suggested that larger muscle groups present lower normalized force fluctuations. The aim of the present study was to test the generalization of these two principles by the assessment of threedimensional force fluctuations of different muscle groups during steady contractions of dorsiflexors, elbow flexors, trunk extensors, knee extensors, and plantarflexors. According to the results, although significant linear correlations exist between MVC forces and the different parameters of variability assessed, no clear relationship was found when the mean values were compared across muscle groups. Moreover, the present data demonstrate that high fluctuations of the task-related force component do not necessarily imply in high fluctuations of tangential components. Hence, factors such as co-contraction and the number of degrees of freedom in the joints might also account for the variability of multidirectional forces. Keywords: Force steadiness, three-dimensional forces, signal-dependent-noise, isometric contractions. Clinical Approbation of a Novel Digital Quality Assurance Method in Digital Radiography Y. Dehtyar, L. Bumbure, T. Kirsanova and L. Shuvalova Riga Technical University/BENI, LMEPB, Riga, Latvia Paul Stradins Clinical University Hospital/MTD, Riga, Latvia Abstract: Quality assurance (QA) of x-ray images and equipment is one of the most important parts of Quality Control System in every hospital. Digital technologies in radiography allow making the QA digitally. A brightness histogram of an x-ray image is a tool, which correlates with digital x-ray image quality parameters. A method of digital QA was established using the tool. A calibration of the method was performed using different x-ray generator s parameters, such as kilovolts and milliampere-seconds. The different focal spots of x-ray tube were in use as well. The current work was performed to check out how well the established method is working in real conditions in hospitals. Different x-ray machines from many hospitals were in use to perform the task of the work. The achieved results show that the method is convenient, stable, objective and reliable for using by medical staff in medical institutions. Keywords: Quality assurance in digital radiography, x-ray image quality, pixels distribution over brightness. MTI 3 5

16 Optagne abstracts ved NBC5 Postural Variability During Pursuit Tracking In Low-Back Pain Patients J.H. Svendsen,, H. Svarrer 3, M. Vollenbroek-Hutten and P. Madeleine Laboratory for Ergonomics and Work-related Disorders, Center for Sensory-Motor Interaction (SMI), Dept. of Health Science and Technology, Aalborg University, Aalborg, Denmark Roessingh Research and Development, Enschede, The Netherlands 3 Department of Rheumatology, Aalborg University Hospital, Aalborg, Denmark Abstract: In low-back pain patients the somato-sensory regulation of quiet stance is altered compared to healthy subjects which in turn results in larger variation in the postural control. In this study, 8 low back pain patients performed postural sways on a force plate to follow a squared shaped track on visual feedback corresponding to 0% of maximum sway in the 4 directions of forward, backward, left and right. The tracking was repeated 4 times and variability- and complexity measures of the center of pressure were calculated and the motor control learning effect was analyzed. The effect of epoch size on the statistical result was also investigated. As the main result through the four tracking trials, variability (calculated as standard deviation of the force output) decreased in both the anterior-posterior direction and the medial lateral direction (p<0.05) and complexity measures (calculated as both approximate entropy and sample entropy) increased for anterior-posterior direction and medial-lateral direction (p<0.05). Secondary, no effect was found for the analysis of different epoch sizes. Results show that a learning effect is present even for 4 repetitions of a postural tracking task. The results presented can be of relevance in training sessions for patients with impaired postural control. Keywords: Balance postural control, tracking, learning effect, sample entropy. Non-linear Imaging using an Experimental Synthetic Aperture Real Time Ultrasound Scanner Joachim Rasmussen, Yigang Du, and Jørgen Arendt Jensen ) Center for Fast Ultrasound Imaging, Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark ) BK Medical Aps, Mileparken 34, Herlev, Denmark Abstract: This paper presents the first non-linear B-mode image of a wire phantom using pulse inversion attained via an experimental synthetic aperture real-time ultrasound scanner (SARUS). The purpose of this study is to implement and validate non-linear imaging on SARUS for the further development of new non-linear techniques. This study presents non-linear and linear B-mode images attained via SARUS and an existing ultrasound system as well as a Field II simulation. The non-linear image shows an improved spatial resolution and lower full width half max and -0 db resolution values compared to linear B-mode imaging on the other systems. For the second scatterer at 47 mm depth the -0 db resolution value for the non-linear SARUS image is mm and.970 mm for the linear image from SARUS. Keywords: non-linear imaging, pulse inversion, synthetic aperture real time ultrasound scanner. Stable Hydrophilic Polydimethylsiloxane Surfaces Produced by Plasma Treatment for Enhanced Cell Adhesion C. Jensen, L. Gurevich, A. Patriciu 3, J. Struijk, V. Zachar and C.P. Pennisi Department of Health Science and Technology, Aalborg University, Aalborg, Denmark Department of Physics and Nanotechnology, Aalborg University, Aalborg, Denmark 3 Neurodan A/S, Aalborg, Denmark Abstract: Polydimethylsiloxane (PDMS) is a widely used polymer for medical implants due to its excellent physical properties, low cost and ease of fabrication. However, in some applications the hydrophobic nature of the material remains an issue. To increase PDMS hydrophillicity, a variety of surface treatments based on plasma discharge have been proposed. In this study, we investigated the effect of water-vapor based plasma on PDMS surfaces. Surface topography was analyzed by means of atomic force microscopy (AFM) while surface chemistry was obtained by Fourier transform infrared spectroscopy (FTIR). To analyze the stability of the treatment, surface wettability was assessed over a period of seven months by contact angle measurement. Furthermore, using primary human fibroblasts, in vitro cell growth and morphology was investigated. It was found that plasma treament produced long-term stable hydrophillic surfaces (contact angle between 70 to 80 ). This property was correlated with hydroxylation of the surface and was accompanied by a slight increase in RMS roughness. Concomitantly, there was a significant increase in the number of cells growing on the plasma-treated surfaces, which was linked with a more spread cellular morphology. The results presented here suggest that water-vapor plasma treatment may be useful to enhance cell adhesion on PDMS implants. Keywords: Biomedical polymers, surface modification, surface chemistry, wettability, cell compatibility.

17 Optagne abstracts ved NBC5 EMG analysis of level and incline walking in Reebok EasyTone ET Calibrator E.F. Elkjær, A. Kromann, B. Larsen, E.L. Andresen, M.K. Jensen, P.J. Veng, and M. de Zee Department of Health Science and Technology, Aalborg University, Aalborg, Denmark Abstract: This study examines () the effect of the Reebok Easytone walking shoe on muscle activity of three large extrinsic muscles compared to walking in a neutral running shoe, and () a comparison of muscle activity when walking on an inclined slope and walking in the EasyTone shoe on level ground. Methods. Ten male subjects participated in a crossover study. A comparative analysis of treadmill walking in a Reebok EasyTone ET Calibrator and a Nike Lunarglide + at zero and % gradient was conducted. Electromyographic (EMG) signals from m. gastrocnemius lateral head (GL), m. biceps femoris (BF), and m. gluteus maximus (GM) of the left leg were processed. Results. This study found no significant (P < 0.05) increase in muscle activity between the two types of shoes. An expected significant increase (P < 0.05) from level to incline walking in GL, BF and GM was observed. Conclusion. Our study did not observe an effect of the Reebok EasyTone shoe on larger extrinsic muscles. Further testing should focus on the shoe s effect on smaller extrinsic muscles. Keywords: Reebok EasyTone, EMG, Level walking, Incline walking. In vivo impedance characterization of a monopolar extra-neural electrode S. Meijs, M. Fjorback and N.J.M. Rijkhoff Neurodan A/S, Aalborg, Denmark Center for Sensory Motor Interaction (SMI), Aalborg University, Aalborg, Denmark Abstract: The impedance of 4 titanium nitride (TiN) coated monopolar extra-neural electrodes has been measured in vivo for a period of 3 weeks. The objectives of the study were to quantify both the electrode-electrolyte interface, as well as the tissue resistance in vivo as a function of time after implantation. Different currents (0.05, 0., 0.5 and 5.0 ma) have been used at frequencies ranging from 0. Hz-00 khz for extensive measurements once a week, while the animals were under anesthesia. The tissue resistance, Rtissue, the faradic resistance, Rf, double layer capacitance, Cdl, and charge transfer ratio between capacitive and faradic processes, Qc/Qf, of the electrode were estimated. For 3 of 4 electrodes, Rtissue could be reliably estimated. The tissue impedance was low in the first week, after which it increased and stabilized. Using an amplitude of 0. ma, charge was transferred predominantly via a capacitive pathway. With increasing current density, the faradic pathways became more dominant and the frequency at which the faradic pathways became more dominant decreased with increasing current density. Rf was higher at higher currents, whereas Cdl was lower at higher currents. The results indicate that when the phase angle approaches 0, Rtissue provides reliable information regarding the healing process. The Qc/Qf curves confirm that the charge transfer mechanism of the TiN electrode interface is mainly capacitive. The mechanism of charge transfer changes towards faradic charge transfer for increasing current density. Both the increasing trend in Rf as well as the decreasing trend in Cdl reaches a plateau at the 0.5 ma. This might indicate that equilibrium is reached between the surface area used for faradic and capacitive charge transfer. The performance of the electrode is comparable to a Platinum/Iridium (Pt/Ir) electrode. Keywords: Neural prostheses, electrochemical impedance spectroscopy, electrical stimulation. Telemedicine for Rural and Underserved Communities of Nepal Ramesh R. Subedi, Carrie B. Peterson and Sofoklis Kyriazakos Center for TeleInFrastruktur (CTIF), Aalborg University, Aalborg, Denmark Abstract: Health workers in rural health care serve most of the population in Nepal, but are isolated from specialist support and access to current medical information. Fortunately, the advent of Information and Communication Technologies (ICT) has unleashed new opportunities for the delivery of health services. In Nepal, there are very remote and less developed communities with limited access to roads and poor infrastructure to access direct health services; here, telemedicine can be taken as the best alternative form to physically travelling and treating people. The strengths of telemedicine (TM) for remote populations include making specialty care more accessible, eliminating lengthy travel and costly transportation, and reducing the cost of some medical services in rural settings. This paper will focus on implications, barriers, proposed solutions, and future extensions of telemedicine in rural and remote places as well as a review on the kinds of services which are most appropriate in the context of Nepal. The main purpose of this paper is to explore practicability of telemedicine in Nepal and its scope of implementation and use. Keywords: Telemedicine, Nepal, Remote and Underserved Populations, ICT, Health care MTI 3 7

18 Optagne abstracts ved NBC5 Use of Sample Entropy Extracted from Intramuscular EMG Signals for the Estimation of Force E.N. Kamavuako, D. Farina, and W. Jensen Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg Department of Neurorehabilitation Engineering, Bernstein Center for Computational Neuroscience, University Medical Center Göttingen, Georg-August University of Göttingen, Göttingen, Germany, Abstract: This study investigates the use of sample entropy as a feature extracted from intramuscular electromyography (EMG) for the estimation of force. Grasping force and intra-muscular EMG) signals were measured in 0 able-bodied subjects. Constraint sample entropy (CSE) was extracted from the EMG signal (window size of 00 ms). The association between the CSE and force was modeled using an artificial neural network. The accuracy of estimation was on average R = 0.89 ± 0.05 and root mean square difference (RMSD) = 6.67 ±.7 N). It was concluded that sample entropy does capture the dynamics in the intramuscular EMG, and that a single channel of intramuscular EMG can be used for muscle force estimation. The information of muscle force is necessary in proportional myoelectric control. Keywords: grasping force, intramuscular EMG, sample entropy, proportional control. Leased Line via Mobile Infrastructure for Telemedicine in India Ujjwal Bania, Carrie Beth Peterson and Sofoklis Kyriazokos Center for TeleInFrastruktur (CTIF), Aalborg University, Aalborg, Denmark Abstract: Telemedicine is the use of information and communication technologies (ICT) to exchange medical information for the purpose of health care and health education. In the context of developing countries, good health care facilities are concentrated in the urban cities, while they are still lacking in rural communities with lower economies. Telemedicine provides a best solution to solve this disparity of health sectors between urban and rural areas. In rural areas of developing countries, a reliable communication link for telemedicine is one of the key challenges. In the recent years, there is an increasing growth of mobile communication in developing countries that has saturated in urban cities and now growing towards the rural areas. This article focuses in India as a developing nation and discusses the cost effective use of widespread mobile communications infrastructure for communication link for telemedicine in rural areas. Keywords: Telemedicine, lease line, India, mobile communication PbS Nanodots For Ultraviolet Radiation Dosimetry Yu. Dekhtyar, M. Romanova, A. Anischenko, A. Sudnikovich, N. Polyaka, R. Reisfeld, T. Saraidarov and B. Polyakov 3 Institute of Biological Engineering and Nanotechnology, Riga Technical University, Riga, Latvia Hebrew University of Jerusalem, Jerusalem, Israel 3 Institute of Solid State Physics, University of Latvia, Riga, Latvia Abstract: Lead sulfide (PbS) nanodots in Zirconia (ZrO ) thin film matrix (ZrO :PbS films) were investigated for UV radiation dosimetry purposes. Samples were fabricated using sol-gel technique. ZrO :PbS films were irradiated with UV light with wavelengths nm during 50 minutes. Photoelectron emission spectra of ZrO :PbS films were recorded and band structure for nonradiated and UV irradiated samples was calculated. It was found that quantity of localized states decreased after UV irradiation while density of localized states was dependent on concentration of PbS nanodots. The observed changes in band structure of ZrO :PbS films after UV irradiation suggest that the films may be considered as an effective material for UV radiation dosimetry, PbS nanodots being the UV sensitive substance of such a dosimeter. Keywords: PbS nanodots, ultraviolet radiation, dosimetry, photoelectron emission. Comparing MRCP of healthy subjects with that of ALS patients Ying Gu, Kim Dremstrup Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark Abstract: The study compared the movement related cortical potential (MRCP) of healthy subjects with that of amyotrophic lateral sclerosis (ALS) patients. We applied the same experimental and analytical methods to 7 healthy subjects and 4 ALS patients. They were asked to imagine right wrist extension at two speeds (fast and slow). The peak negativity and rebound rate were extracted from MRCP. Significance test showed that the healthy presented higher peak negativity during fast movement imagination than ALS. In addition, the healthy showed stronger rebound rate than ALS during both fast and slow movement imagination. Weak rebound rate might reflect the impairment of motor output pathway. Keywords: Electroencephalography (EEG), Movement related cortical potential (MRCP), motor imagery, Brain computer interface (BCI) and amyotrophic lateral sclerosis (ALS).

19 Optagne abstracts ved NBC5 Investigation of the Linear Relationship between Grasping Force and Features of Intramuscular EMG M. F. Bøg, E. Erkocevic, M. J. Niemeier, J. R. Mathiesen, A. Smidstrup, and E. N. Kamavuako Department of Health Science and Technology, Aalborg University, Aalborg, Denmark Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark Abstract: Surface electromyography (semg) can be used to control prosthetic devices. However, intramuscular EMG (iemg) has been proposed as an alternative control signal, since it provides advantages such as electrode implantation and more selective recordings. iemg can potentially be used to develop more intuitive prosthetic devices but since only limited research is available within this area, further investigation is needed on the relationship between iemg and force. An earlier study quantified the linear relationship between iemg and grasping force, however, this was solely based on one feature and force ranging from 0-50 N. Therefore the aim of the present study was to quantify the linear relationship between grasping force and 4 different EMG features using the entire force range from 0 to 00 % Maximum Voluntary Contraction (MVC). Single-channel iemg and semg were recorded concurrently from the muscle Flexor Digitorum Profundus (FDP) from subjects who exerted four force profiles during power grasping. The Wilson Amplitude (WAMP) feature showed the best results for both semg and iemg ( > 0.9), where semg had a significantly higher mean -value than iemg (P = 0.044). However, the potential of using iemg should be investigated further based on the predictive capabilities of the features. Keywords: Surface EMG, Intramuscular EMG, Power grip, Flexor digitorum profundus, Linear relationship. Developments towards a Psychophysical Testing Platform a computerized tool tocontrol, deliver and evaluate electrical stimulation to relieve phantom limb pain B. Geng, K.R. Harreby, A. Kundu, K. Yoshida,, T. Boretius 3, T. Stieglitz 3, R. Passama 4, D. Guiraud 4, J.L. Divoux 5, A. Benvenuto 6, G Di Pino 6, E. Guglielmelli 6, P.M. Rossini 6,7 and W. Jensen Department of Health Science and Technology, Aalborg University, DK Biomedical Engineering Department, Indiana University-Purdue University Indianapolis, USA 3 Department of Microsystems Engineering, University of Freiburg, Germany 4 Laboratoire d Informatique, de Robotique et de Microelectronique de Montpellier, France 5 MXM Neuromedics, France 6 Università Campus Bio-Medico di Roma, Italy 7 IRCCS S. Raffaele-Pisana, Italy. Abstract: Phantom limb pain (PLP) frequently follows amputation. Artificially inducing phantom hand sensations by electrical stimulation may reduce PLP. The use of implantable, multi-channel microelectrodes provides the opportunity to selectively activate sensory fibres. However, combinations of variables from a multichannel stimulation system can produce a huge number of possible stimulation paradigms. It makes the use of psychophysical evaluation of the evoked sensations an impractical and time-consuming task in the clinical setting. Our aim is to develop a computerized, automatic, psychophysical testing platform to support control, delivery and evaluation of the electrical stimulation for PLP relief. Keywords: Phantom limb pain, psychophysical test, multichannel electrical stimulation. Meat Cutting Tasks Analysis Using 3D Instrumented Knife and Motion Capture C. Pontonnier,, M. de Zee, A. Samani, G. Dumont, 3 and P. Madeleine Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, DK-90 Aalborg, Denmark VR4I project team, IRISA, Campus de Beaulieu, F-3504 Rennes Cédex, France 3 ENS Cachan Antenne de Bretagne, Campus de Ker Lann, F-3570 Bruz, France Abstract: This article presents a complete experimental setup and pipeline designed to analyze kinematics and dynamics of meat cutting tasks in terms of musculoskeletal disorder appearance risk. An instrumented knife records the cutting force in 3D. A motion capture system assesses trunk and arm motion in 3D. Finally, the AnyBody software is used to run an inverse dynamics analysis on the recorded motions to obtain muscle forces. At last, EMG records are set up on most of relevant superficial muscles of the shoulder-neck area in order to validate the results. Sample results are proposed for standard workspace parameters, showing the relevance of the information for assessing the risk of developing work-related musculoskeletal disorders. Keywords: Movement analysis, Inverse Dynamics, External Forces, Muscle Forces, Ergonomics MTI 3 9

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